<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    var damu ="达姆";
    xfz="晓飞张";

    console.log(Object.getOwnPropertyDescriptor(window,"damu"))
    console.log(Object.getOwnPropertyDescriptor(window,"xfz"))

    delete window.damu;
    console.log(window.damu)
</script>
</html>